According to the census, 11.4% of all housing units in the U.S. are vacant. A county supervisor wonders if her county is different from this. She randomly selects 850 housing units in her county and finds that 129 of the housing units are vacant.
a) The county supervisor would like to see if her county has a different rate of vacancy in its housing units. State an appropriate null hypothesis and alternative hypothesis for her to consider as the framework for a one-proportion z-test
b) calculate the test statistic (the z score of the observed vacancy rate, in this case) and place it with